In a vehicle, for example, an automobile, the direction of radiation of a lamp is appropriately changed in accordance with the running conditions.
For example, a structure that enables a head lamp unit to be rotated to the left and right directions and an actuator that rotates the lamp unit in the left and right directions may be provided, and when the automobile is turning, the direction of radiation of the lamp unit may be turned.
Unexamined Japanese Patent Publication No. 2002-160581 proposes an actuator for driving a lamp unit in order to achieve this.
The actuator disclosed in Japanese Patent Publication No. 2002-160581 is configured from a motor; an output shaft that rotates the lamp unit; a drive mechanism portion including a transmission gear system that transmits the rotation of the motor to the output shaft; and a control circuit portion that controls the drive of the motor, disposed in a housing. The lamp unit is connected to the output shaft such that, for example, in response to a steering operation, the motor is driven and controlled by the control circuit portion, and, in accordance therewith, the output shaft is rotated by a predetermined angle in a predetermined direction so as to rotate the lamp unit by a predetermined angle in a predetermined direction.
However, in the prior art actuator, the motor, the drive mechanism portion including the gear, and the control circuit portion are disposed within the same space. As a result, a problem has become apparent in that grease, oil, and the like, that are used in the drive mechanism portion adhere to electronic components on the board of the control circuit portion, thus causing deterioration of the circuit. Moreover, other problems occur such as the performance of the structural components of the drive mechanism portion being impaired as a result of cutting debris of the board of the control circuit portion becoming jammed in the gears of the drive mechanism portion.